PllOCEEDINGS OF THE 



Ills election as a Poreio;n Member o£ onr Society is dated 

 2nd May, 1870- He died at Florence, 4th December, 1898, 

 aged 68. 



CxVKL CLA.US, whose name will always be famous in Zoology 

 as a pioneer-investigator of the Crustacea and a foremost student 

 of the Coelenterata, died on January 18th, 1899, in his 65th 

 year. He was born at Kassel in January 1835, and studied at 

 the Universities of Marburg and Griessen, at the latter under 

 Leuckart, among whose pupils he was one of the most distin- 

 guished. In 1858, the year following that in which Claus took 

 his deo-ree, he was appointed Privat-Docent for Zoologv at 

 Marburg, passing in the following year to Wiirzburg, where in 

 1860 he was made a Professor Extraordinarius. In 1863 he 

 returned to Marburg, to fill the office of Ordinary Professor of 

 Zoology, and he was subsequently called to Grottingen (1870) and 

 Vienna (1873). It was in the latter University that he produced 

 most of the work by which he will be best remembered, and 

 durino' the 23 years he held office his Laboratory was the scene 

 of a ceaseless "activity, a centre of attraction to zoologists of all 

 nations. In his younger days Claus was an enterprising marine 

 zoologist — Heligoland, Naples, and Messina being noteworthy as 

 localities which he visited ; and in later years he founded the 

 Zoological Station at Trieste, one of the oldest and most 

 honoured of Marine Observatories, the resources of which he 

 turned to special use in his ordinary class-work. He retired 

 into private life in 1896, distinguished as an investigator, and by 

 the student beloved, as the writer of a text-book which, unlike 

 most Grerman works of its kind, was something more than a 

 mere compilation and had a freshness and originality peculiarly 

 its own. 



The 40 years of Claus's active life witnessed the publication 

 of a vast number of scientific papers and monographs, many of 

 which will remain classical and among the most representative 

 examples of the zoological literature of the period. His In- 

 aut'ural Dissertation, published in 1857, was upon ' The Genus 

 Cyclops and its indigenous Species ' ; and his last noteworthy 

 paper was devoted to the maxillary appendages of the Copepoda 

 and the morphology of the Cirripede limbs. Of the numerous 

 new genera and species he in the meantime described, of his 

 revolutionary classifications, his elaborate studies of the morpho- 

 logy of all parts of the Crustacean skeleton, of his fascinating 

 work upon the anatomy and histology of the heart and internal 

 organs of certain microscopic forms, and of the importance of 

 that upou the larval nervous system, it is but necessary to re- 

 mind the trained zoologist, to whom everything he wrote came 

 PS a relief, a biight inspiration, which rendered clearer some in- 

 volved corner in the mighty maze of Crustacean life. The 

 Structure and Development of the Parasitic Crustacea, the Free- 



